Successful mediastinal teratoma resection in a child by assisted VATS: a case report

Abstract

Background

Video-assisted thoracic surgery (VATS) is widely used for thoracic lesions in pediatric patients. VATS is also applied to pediatric mediastinal tumors if there is no adhesion or invasion between the tumor and adjacent neuronal and cardiovascular structures. Here, we present a pediatric case of mediastinal teratoma in which the tumor adhered to the superior vena cava, and resection was safely completed using assisted VATS, an integrated surgical approach comprising mini-thoracotomy with video assistance.

Case presentation

A 9 year-old girl presented with right shoulder pain. Chest radiography and computed tomography revealed a 5.4 × 5.1 × 5.8 cm mass in the right upper anterior mediastinum. She was presumed with a mature teratoma, and resection was performed by assisted VATS with muscle sparing axillar skin crease incision (MSASCI) for a mini-thoracotomy. The procedure was safely completed, with the patient discharged on postoperative day 5. At 1 year postoperatively, there was no recurrence with excellent motor and cosmetic results.

Conclusions

The combination of MSASCI and VATS would be useful not only for mediastinal teratomas but also for other mediastinal tumors and almost all other thoracic lesions in pediatric patients.

Background

Video-assisted thoracic surgery (VATS) is widely used for thoracic lesions in pediatric patients, including congenital cystic adenomatoid malformation and extrapulmonary sequestration [1]. The advantages of VATS include low postoperative pain, few surgical wounds, and short hospital stays [2]. VATS is also applied to pediatric mediastinal tumors if there is no adhesion or invasion between the tumor and adjacent neuronal and cardiovascular structures such as the phrenic nerve and superior vena cava [2, 3]. An integrated surgical approach comprising mini-thoracotomy with video assistance, called assisted VATS, is safe and adequate for mediastinal tumors with adhesion or invasion to the adjacent structures [3, 4]. Here, we present a pediatric case of mediastinal teratoma in which the tumor adhered to the superior vena cava, and resection was safely completed using assisted VATS.

Case presentation

A 9 year-old girl presented with pain in her right shoulder, and chest radiography and computed tomography showed a mass (5.4 × 5.1 × 5.8 cm) in the right, upper, and anterior mediastinum (Fig. 1a, b). The mass was encapsulated, and contained fatty components and calcifications (Fig. 1b). Blood test results showed alpha-fetoprotein levels < 2 ng/mL, β-human chorionic gonadotropin levels < 0.2 mIU/mL, and neuron-specific enolase levels at 18.2 mg/mL. The patient was presumed with a mature teratoma, and resection was performed using assisted VATS under one lung ventilation because the boundary between the tumor and the superior vena cava was not clear and potential adhesions were suspected. (Fig. 1c, d). A mini-thoracotomy was performed by a 4-cm muscle sparing axillar skin crease incision (MSASCI) through the fourth intercostal space, and two 5-mm ports, one for thoracoscope and the other one as assistant port, were introduced through the eighth intercostal space (Fig. 2a). We retracted the mini-thoracotomy by using both a wound retractor and a small Finochietto retractor. The tumor was dissected from pleura by monopolar cautery through the mini-thoracotomy with the assistance of laparoscopic forceps and thoracoscope. The tumor adhered to the right phrenic nerve and the superior vena cava. The right phrenic nerve remained intact with blunt dissection and the tumor was safely dissected from the superior vena cava and resected from thymus by using monopolar cautery and the LigaSure Vessel Sealing System (Valleylab, Boulder, CO, USA) through mini-thoracotomy with the assistance of laparoscopic forceps and thoracoscope (Fig. 2b). Finally, a chest tube was inserted through the assistant port and fixated fourth intercostal space. The operative time was 290 min, and the intraoperative blood loss was 10 mL and there was no need of postoperative ventilation. The operative time was longer than expected because the dissection of the cranial side of the tumor was challenging with poor visualization and we checked there was no invasion of the tumor to the brachial neurovascular bundle. The pathological diagnosis was a mature teratoma, and the margin was negative for tumor tissue (Fig. 2d). Exudative pleural effusion gradually decreased and the chest tube was removed on postoperative day 3, and the patient was discharged on postoperative day 5. There was no recurrence 1 year after the operation, and the patient was satisfied with the cosmetic results (Fig. 2c).

Fig. 1

a, b Chest radiography and computed tomography images show a mass (5.4 × 5.1 × 5.8 cm) in the right, upper, and anterior mediastinum in a 9 year-old girl. The mass was encapsulated, and contained fatty components and calcifications. c, d The boundary between the tumor and the superior vena cava was not clear and potential adhesions were suspected (arrow)

Fig. 2

a The schema of incision and the port for assisted video-assisted thoracic surgery (VATS). A mini-thoracotomy is performed by creating a 4 cm muscle-sparing axillar skin crease incision through the fourth intercostal space, and two 5 mm ports are introduced through the eighth intercostal space. b During the operation, the tumor shows adherence to the right phrenic nerve and superior vena cava. The right phrenic nerve is kept intact, and the tumor is safely removed by assisted VATS. c The scar of the muscle-sparing axillar skin crease incision one month after surgery. d The pathological diagnosis is mature teratoma, and a negative surgical margin is obtained

Discussion and conclusions

Mediastinal tumors have no obvious symptoms in the early stage. When symptoms such as respiratory distress and chest pain occur, the tumors develop to a larger size, with adhesion or invasion of adjacent neuronal and cardiovascular structures [5]. The large size of the tumor compared with the small size of the thoracic cage and adhesion or invasion with adjacent vital organs prevents the performance of complete VATS for mediastinal tumors in pediatric patients [3]. Assisted VATS ensures the operation performed safely than complete VATS with lower risk of bleeding in cases of large tumors or tumors with adhesion or invasion [4]. Moreover, mediastinal tumors are located deeper than the lateral or axillary incision, and the three-dimensional view provided by assisted VATS is considered suitable. In our case, the tumor was large, and severe adhesions were observed with the superior vena cava; thus, assisted VATS enabled successful resection. In this case, we performed a MSASCI for mini-thoracotomy. Posterolateral or standard axillary incisions for pediatric thoracic surgery occasionally result in poor motor and cosmetic outcomes, including chest deformities (scoliosis, shoulder deformity, and winged scapula) and large surgical scars [6]. Recently, the use of MSASCI in pediatric thoracic surgery has been reported, with excellent motor and cosmetic results [6]. In our case, no motor complications occurred, and the patient was satisfied with the cosmetic results. The MSASCI approach can be extended downward to eight intercostal spaces, and lesions located in the upper to lower mediastinum can be treated [6].

In our case, the tumor was a mature teratoma without malignancy; however, the coexistence of malignant components in mature teratomas has been reported, where complete resection was necessary [7]. If the tumor is suspected as malignancy and invades to mediastinal structures, we should choose conventional open approaches such as median sternotomy, semi-clamshell incision and anteriolateral thoracotomy.

In summary, VATS has been increasingly used to treat various thoracic lesions in pediatric patients. However, mediastinal tumors are occasionally difficult to resect using complete VATS because of their size and adhesion or invasion of important adjacent structures. Our approach, the combination of MSASCI and VATS, would be useful not only for mediastinal teratomas but also for other mediastinal tumors such as neuroblastomas and almost all other thoracic lesions in pediatric patients.